I use a wattmeter to measure the power-consumptions of my computers. The following is the result:
my laptop + Ubuntu 14.04: 14.5 watt my laptop + ArchLinux: 30 watt my laptop + Bios Setting: 45 watt my laptop + Ubuntu 14.04(init=/bin/bash): 31 watt my laptop + ArchLinux(init=/usr/bin/bash): 33 watt my old laptop + Ubuntu 14.04: 21 watt my old laptop + Ubuntu 16.04: 24 watt my old laptop + ArchLinux: 19 watt my old laptop + Bios Setting: 22 watt PS: my laptop(CPU: i5-2410; BIOS: AMI A0.18; Board: TSINGHUA TONGFANG CO.,LTD) my old laptop(CPU: Pentium Dual-core cpu T4200; Board: LENOVO; Board: LENOVO)
all the data except when it is in Bios Setting modes are collected while the environments are idle waiting for user commands and the CPU rate is very low.
I want to tune my ArchLinux use the same or even less power than Ubuntu-14.04. I have tried cpufreq, phc-intel, and compiled my own linux kernel but nothing worked. I tried to run
powertop --auto-tune, and both ArchLinux and Ubuntu-14.04 reduce power consumption by about 2-3 watt.
Here is the boot message related to ASPM of my laptop:
> dmesg | grep -i aspm [ 0.162661] acpi PNP0A08:00: _OSC: OS supports [ExtendedConfig ASPM ClockPM Segments MSI] [ 0.162746] acpi PNP0A08:00: _OSC failed (AE_ERROR); disabling ASPM [ 3.323580] r8169 0000:04:00.0: can't disable ASPM; OS doesn't have ASPM control
It's strange to note that my laptop in bios setting mode consumes 45watt. And there must be something to do with user space services, since both Ubuntu-14.04 and ArchLinux consume about 30 watt when they are init to /bin/bash. Could you explain why it's so high? Thank you.